Serum Biomarkers of Clinical and Cytologic Response in Dogs with Idiopathic Immune-Mediated Polyarthropathy

Immune-mediated polyarthropathy (IMPA) is a common disorder of the immune system causing pyrexia and a shifting lameness. Response to treatment can be monitored by serial joint taps. This study examined the utility of measuring serum parameters as a marker for the level of joint inflammation. Nine dogs with idiopathic IMPA were compared with 6 healthy controls in a prospective study. Plasma C-reactive protein (CRP), interleukin-6 (IL-6) and interleukin-8 (CXCL8) were measured at the start of treatment, and 2 and 4 weeks after treatment with prednisolone. Arthrocentesis was also performed at these three times points, and a canine brief pain inventory (CBPI) and accelerometry measurements were performed to assess lameness and mobility. CRP was found to be higher in dogs with IMPA than controls, and was lower by week 2 of treatment. CRP correlated with CBPI scoring, joint cellularity and mobility as measured by accelerometry. IL-6 was also found to be higher in dogs with IMPA than controls, and was lower by week 4 of treatment. CXCL8 was not significantly different between dogs with IMPA and healthy controls.

Bottom line: Measurement of plasma CRP and IL-6 show potential as markers of level of joint inflammation and of response to treatment.

Idiopathic pulmonary fibrosis (IPF)is a lung disease particularly affecting West Highland White Terriers. It is incurable, and leads to progressive fibrosis of the pulmonary interstitium. This prospective case-control study aimed to evaluate survival, prognostic factors and exercise tolerance in dogs with this disease. 15 West Highland Whites were included in the study, with 11 healthy controls. The 6-minute walk test was used to evaluate exercise tolerance. Of the seven dogs with IPF that died during the study, the median survival time was 32 months from onset of clinical signs. The authors did not find any significant prognostic factors in this study. Dogs with IPF were found to walk a shorter distance in the 6 minute walking test than healthy controls, and it was found that the arterial oxygen levels were correlated with distance walked in dogs with the condition.

Bottom line: This study demonstrated that IPF reduces life expectancy, though there is a considerable variation in survival of individuals. It also showed that the 6 minute walking test is a useful test of exercise tolerance.

Various histopathological types of oral tumours can be categorised as odontogenic neoplasms. This study evaluated the computed tomography (CT) findings of different odontogenic neoplasms of dogs. A blinded radiologist reviewed the images of 29 dogs, 23 of which also had dental radiographs. 96% of the tumours were directly associated with or in the region of multiple teeth, and a similar amount showed contrast enhancement. Alveolar bone lysis and tooth displacement due to the mass were also very common. Mass-associated cyst-like structures were only found in tumours containing odontogenic epithelium. 15 canine acanthomatous amelobastomas were identified, 10 of which were extra-osseous and 5 of which were intra-osseous. The intra-osseous forms were more likely to have associated cysts and appeared more aggressive. Amyloid producing odontogenic tumours and fibromatous epulides were also found, although the authors note that the latter were rarely referred for CT. Dental radiographs were useful for evaluating mass-associated tooth destruction but extra-oral tumour extension was seen more easily on CT.

Bottom line: CT has a valuable role in evaluating the type and extent of odontogenic neoplasms in dogs.

The SNAP canine pancreatic lipase ( SNAP cPL) and specific canine pancreatic lipase (Spec cPL) tests are commonly used to aid in the diagnosis of pancreatitis. This prospective observational cohort study aimed to assess the diagnostic accuracy of these tests, as well as examine the agreement between these two tests in dogs presenting to the emergency centre of a university teaching hospital with acute abdominal signs. 38 dogs were included in the study, and the final diagnosis was known in each case. They were grouped according to presence or absence of acute pancreatitis. The SNAP cPL sensitivity was 82% and the specificity was 59%. The spec cPL sensitivity was 70% and the specificity was 77%. There was a good agreement between the two tests, but four cases were positive on the SNAP cPL and negative on the spec cPL.

Bottom line: Up to 40% of dogs presenting with acute abdominal disease may have a false positive on SNAP and Spec cPL tests.

Pulmonary thromboembolism is probably an underdiagnosed condition given the challenges of making a diagnosis, although it is often suspected on clinical grounds as a sequel to various medical conditions. This prospective study aimed to assess whether computed tomography (CT) pulmonary angiography could assist in identification of pulmonary thromboembolism. 12 dogs were included in the study, all of which had immune-mediated haemolytic anaemia and respiratory distress. Under sedation, spiral CT pulmonary angiography was performed with a 16 slice scanner using a pressure injector to administer contrast through a peripheral intravenous catheter. Other tests included echocardiography, arterial blood gas analysis, thromboelastography, D-dimers and cardiac troponins. Four dogs were diagnosed with pulmonary thromboembolism based on predefined criteria, having discrete filling defects in their main or lobar pulmonary arteries. Three were suspected to have pulmonary thromboembolism and five appeared not to have, based on the scans. None of the other tests discriminated for pulmonary thromboembolism, although the authors note the sample size was small.

Bottom line: CT pulmonary angiography can be performed under sedation even in dogs with respiratory distress and is useful to rule in and out pulmonary thromboembolism in dogs.

Pericardial effusion is a commonly encountered disease which can be classified as benign/idiopathic, or secondary eg to neoplasia. This retrospective study aimed to assess the success of treating cases of pericardial effusion caused by right atrial masses with doxorubicin as a sole agent. Exclusion criteria included surgery such as pericardiectomy or mass resection. The median survival time was 140 days, with a range from 2 to 302. Side effects from the chemotherapy were common but mild.

Bottom line: The authors conclude that single agent doxorubicin is a viable treatment option for dogs with right atrial masses causing pericardial effusion.

Administration of buprenorphine by mouth for absorption across the buccal mucosa is commonly used as a method of analgesia in cats. This study evaluated the bioavailability of the opioids morphine, methadone, hydromorphone and oxymorphone after buccal administration. Six healthy adult female neutered cats were included in the study. All the cats received all the drugs at different times, and arterial blood samples were taken prior to administration and at various time intervals up to 8 hours. The mean bioavailabilities of the morphine, methadone, hydromorphone and oxymorphone were respectively 37, 44, 22 and 19. The bioavailability of methadone was found to be significantly higher than oxymorphone via this administration route.

Bottom line: This study evaluates the bioavailability of buccally administered opioids for pain relief in cats.

Anterior uveitis can be idiopathic, but also has a number of local or systemic causes. This study of 12 dogs and 10 cats evaluated the utility of cytology of the aqueous humour, obtained by aqueocentesis, in the diagnosis of underlying causes of anterior uveitis. It was found that the duration of the disease was not significantly different in dogs that had an underlying cause identified compared to those with idiopathic anterior uveitis, but in cats the disease duration was shorter in those patients with FIP than those with idiopathic disease. Aqueous humour cytology allowed the diagnosis of neoplasia in two dogs, but was not diagnostic in any of the cats. Although cytological changes were seen in cats with FIP, there were no significant differences between these cats and those with idiopathic uveitis.

Bottom line: Aqueous humour cytology is useful to detect neoplasia in dogs, but may not be useful in cats.

Shivering is a poorly defined movement disorder, predominantly affecting draught breeds of horses. This study utilises videos of movement disorders in horses to provide a detailed description of shivering and to subjectively characterise the movement of the hindlimbs to allow comparison with other movement disorders, such as stringhalt. The videos of 70 horses walking forwards and backwards in hand, turning sharply in both directions and having hindlimbs lifted manually were reviewed; the stride movement was assessed both subjectively, and semi-quantitatively where the stride was representative and the camera angle was standardised. The subjective analysis allowed shivering to be categorised into the following groups- standing hyperflexion (hyperflexion upon lifting hindlimbs, normal gait), shivering hyperextension (hyperextension of hindlimbs upon walking backwards), shivering hyperflexion (hyperflexion of hindlimbs when walking backwards) and shivering forward hyperflexion (similar to hyperflexion, with additional hyperflexion during forward walking). These cases could be differentiated from stringhalt cases, which had bilateral, exaggerated stifle and hock flexion during every forward and backward stride. The semi-quantitative assessment found that horses with shivering hyperflexion, forward hyperflexion and stringhalt all showed a prolonged swing phase of the gait during backward walking. These different presentations of shivering may represent differing severity of disease or different neurological conditions.

Bottom line: A diagnosis of shivering is based on the clinical signs of difficulty reversing, with muscle hypertonicity that results in either hindlimb hyperflexion or extension; a diagnosis should not be made on the basis of hyperflexion only exhibited when the limb in manually lifted.

It is well acknowledged that following one episode of colic, a horse is at risk of further episodes in the time period following the initial episode. This study looked at a population of horses (59 colic cases and 177 controls) and over time in order to identify risk factors for recurrent colic. Of the horses with recurrent colic, the median time to the first recurrence was 101 days, with between 2 and 5 recurrences occurring over the study period. An increasing time spent at pasture was found to have a protective effect on the risk of recurrence, with almost linear relationship between increased time at pasture and decreased risk of colic recurrence. There was an increased risk in horses who displayed stereotypic behaviours such as weaving and windsucking. In this group, feeding fruit and vegetables had a protective effect, although it is not known if this is due to differing management approaches rather than the specific feeding practice. Unlike previous studies, the temporal effect of risk factors was examined here by the use of a nested case control design, which allowed exposure to the various risk factors to be recorded prior to the colic episode.

Bottom line: Horses which display stereotypical behaviours (crib biting, windsucking or weaving) or who have minimal access to grazing are at increased risk of recurrent colic.